Rotary pump



Feb. 26, 1957 L. B. HO'JBERG 2,78225 ROTARY PUMP Filed May 1S, 1954 2 sheets-sheet 1 20 LIL/27%,;

IIY VEN TOR. V LA URE/VC/O B. NOx/BERG Feb. 26, 1957 B. HoJBx-:RG 2,78%725 ROTARY PUMP Filed May 18, 1954 2 Sheets-Shea?l 2 INVENTOR. LAUEENc/o a Hch/13H26 ROTARY PUMP Laurencio Brchner Hjberg, Vicente Lopez, Province of Buenos Aires, Argentina Application May 18, 1954, Serial No. 430,633

Z Claims. (Cl. S-137) My present invention refers to certain new and useful improvements in rotary pumps of the type comprising a cylindrical casing with a rotor eccentrically mounted therein and provided with slidable spring-loaded blades or wings capable of delivering a liquid from an inlet to a discharge port of said casing.

The known pumps of the type referred to are in general disadvantageous insofar as they are to be operated at a relatively high speed in order to ensure a reasonable output. The high speed rotation of the blades or wings, however, produces undesirable effects of turbulence and in View hereof these pumps are not recommendable for being used in connection with liquids such as milk, beer, wine, oil, etc. which are not to be excessively stirred.

In the known rotary pumps comprising an eccentrically mounted rotor with radially projecting wings, the rotor is mounted on the driving Yshaft and is provided with radial slots wherein the wings are slidably mounted. The combined action of pressure springs arranged on the bottom of said slots and of the centrifugal force developed by the rotation of the rotor urges the wing outwardly into contact with the inner surface of the cylindrical pump casing. This centrifugal force, at the one hand, requires the rotor to be operated with high speed. At the other hand, the driving shaft which extends through the rotor and which disadvantageously reduces the depth of the afore-mentioned slots renders the use of relatively broad wings impossible, and in view hereof the eccentricity of the rotor with regard to the pump cannot be increased beyond a limit determined by the depth of the slots in proportion to the breadth of the wings, because it is evident that the wing portion engaged by the slot has to be always substantially larger than that wing portion protruding from said slot in order to ensure a perfect guiding of the wings and to avoid distortion of the same during operation. It is thus evident that in the known rotary pumps their output cannot be increased by an increase of the eccentricity, but only by increasing the number of revolutions of the rotor with the disadvantageous result that the use of these pumps is restricted to such liquids which are not affected by stirring.

The main object of my present invention is to provide an improved rotary pump of the type referred to, whereinl the rotor in the form of a drum is composed of two symmetrical coaxial halves. These drum portions are rotatively supported by individual shaft members, with the advantageous result that in this improved vpump the rotor is not mounted on its driving shaft passing through the centre thereof, and that by virtue hereof the slot for housing two radial blades or wings which extend radially right through the rotor may be of substantially greater depth.

Another important object of the invention is to provide an improved rotating pump of the type referred to, wherein the rotor in the form of a drum is provided with a narrow passage which diametrically or radially extends through said drum and over the whole length of nited States Patent O rice the same for housing one pair of opposite wings which under the action of spring means arranged between the same protrude from the openings of said passage at the circumference, with the advantageous result that said wings are efficiently guided over a relatively very great portion of their outer surfaces and are enabled to protrude from the rotor circumference to an extent equal two times the amount of eccentricity of the rotor with regard to the pump casing. This advantageous feature permits, at the one hand, of a considerable increase of the output of the pump and, at the other hand, if such increase is not desired, a proportional reduction of the number of revolutions of the rotor. The rotation speed of the wings may be decreased so far that the undesired effects of the turbulence likely to be produced by said wings when rotating with high speed may be avoided without decreasing the output of the pump. An additional advantage ensured hereby consists in that the correspondingly decreased centrifugal force acting upon the radial wings diminishes the wear of the outer edges of the wings in contact with the inner surface of the cylindrical pump casing.

An additional object of the invention is to provide. an improved rotary pump of the type referred to, wherein the end walls of the rotor are formed with outwardly projecting reinforcement and sleeve portions and wherein the end walls of the pump casing, one of these last-mentioned end walls constituting a removable cover, are formed with shoulder and sleeve portions, the arrangement of these end walls of said rotor and said casing being such that, at the one hand, the rotor is perfectly guided and rotatively supported within the pump casing and that, at the other hand, the rotor may be effectively connected to a pair of opposite shafts, one of which constitutes the driving shaft and the outer one a supporting shaft of the rotor.

In this arrangement, according to a further advantageous feature of the invention, the connection of the rotor with the driving shaft is performed in a detachable manner with the result that after removing the cover of the pump casing the rotor body may be readily taken out. This feature is of particular importance if the pump is used for handling liquids such as milk, oil, beer, Wine, etc., because the pump may be readily cleaned after use and, if desired, the rotor may be easily changed by another one.

With these objects and advantageous features in view my present invention comprises the arrangement, combination and construction of parts as will be hereinafter fully described with reference to the accompanying drawings wherein a preferred embodiment of the invention has been illustrated by way of example only and wherein Figure l is a longitudinal sectional view of the improved pump according to the invention, this section being taken along the line 1 1 of Figure 3;

Figure 2 is a side and partly sectional view of the rotor body of the pump shown in Figure 1;

Figure 3 is a cross-sectional View of the pump along the line 3`3 of Figure l, and

Figure 4 is an end view of the rotor body of the pump showing that end of the rotor engaged by the driving shaft of the pump. l

The rotary pump with radial slidable wings according to my invention and in its embodiment as shown on the accompanying drawings comprises a cylindrical casing 1 provided with suitable supporting members 2 and conveniently produced by casting so that these members and said casing form lan integral body. One end of the casing 1 is closed by the end wall 3, whereas its opposite open end may be tightly closed by a cover 4 held in place by cylindrical easing body.

The cylindrical casing body `1 is provided with intake and discharge ports 6 and 7, respectively, so arranged that the tlow of the liquid passing there-through is in a direction substantially .tangential to the cylindrical wall of lthe casing. The ports 6 and 7 are conveniently provided with internal screw threads as shown at 8 and '9, respectively, for connecting the pump with suitable supply and discharge pipes (not shown).

The end wall 3 and the cover 4 of'the casing 1 are so constructed that they form each an annularshoulder 10 in order to provide for an inner cylindrical recess 11, and sleeve portions 12 and 13, respectively, constituting bearing members for a driving shaft 14 and a supporting shaft 15, the arrangement of sai'd shoulder as well as of said sleeve members being eccentrical with regard to 'the axis of the cylindrical casing body 1. The sleeve portion 12 contains a packing ring 16 secured in place by means of a screw cap 17 or the like. This arrangement permits of an eccentric mounting of the pump rotor within the casing 1 by means of the afore-mentioned shafts 14, 15.

One of the characteristic features of my invention consists of the provision of two separate shaft members 14, instead of a single vshaft as employed in the known rotary pumps. VBy virtue of this feature the pump rotor 18 may be provided with a narrow passage 19 which diametrically extends through the rotor body as shown in Figures 1 and 3.

The rotor 18 as shown in Figure 2 is composed of two halves secured together by means of overlapping recessed end portions as indicated at 18; and the end walls are formed each With an annular reinforcement 20, 20 and with an outwardly projecting sleeve portion 21, 21 for receiving the shafts 14, 15 of which the supporting shaft 15 may -be xedly secured in its respective sleeve portion 21', whereas the driving shaft 14 `provided with a noncircular axial extension 22 engages a correspondingly recessed clutch member 23 fixed within 'the sleeve portion 21, with the advantageous result that after removing the cover 4 the rotor 13 may be readily withdrawn e. g. for cleaning or other purposes. Any other manner of carrying out a suitable detachable connection between the-shaft and the rotor may be used without altering the principle of the present invention. The annular reinforcements 20, 20 co-operate with the edges formed by the cylindrical recesses 1-1 for the purpose of guiding and additionally supporting the-rotor 18.

The passage 19 which diametrically extends through the rotor 18, is formed between two parallel inner Awalls 24 and by opposite recesses 25 of the end walls Vof the rotor as clearly shown -in lFigure l.

The passage 19 constitutes the housing rvfor the slidable blades or wings 26, 26 which are provided lwith opposite recesses containing pressure springs 27 capable of maintaining said blades in contact with the inner surface of the cylindrical wall of the casing 1, the blades orwings 26,726 as shown in Figures 1 and 3 are of a width equal the width of the rotor and vof a length slightly less than the inner radius of the pump casing. T he thickness of the blades or wings is but slightly less than the width of the passage 19. As the opposite surfaces of these blades are in constant contact with the walls 24, the wear of said blades is reduced to a minimum.

It is evident that the two blades or -wings 26, 26 act as a unit which during-each revolution of the rotor 18 reciprocates radially within the passage 1'9 kof the rotor body and that the stroke of reciprocation of said blades or wings is twice the amount of the eccentricity of the rotor with regard to the pump casing, whereas the relative movement of the wings is reduced to e. g. about M3. By virtue of the arrangement of the blades or wings 26, 26 with a relatively small distance between the same and in such a manner that they reciprocate as a unit due to their interconnection by the springs 27 in the passage v1-9 of the rotor 18, the major .portion of thewingrunit is 4 housed in said passage and this feature is very advantageous insofar as it permits of a considerable increase of the eccentricity over the limits admitted by the hitherto known constructions. As a result hereof the eccentricity may be increased to about three times the eccentricity of the known pumps and the capacity of the free space left between the rotor and the pump casing is thereby increased in the proportion of the square of the difference between the radius of the rotor and of the pump casing. By virtue of -this increase of capacity and therewith of the volume of liquid delivered by the pump, it is now possible to considerably reduce the number of revolutions of the rotor and at the same time of the flow speed of the liquid in the pump casing to such a degree that the same will be equal the flow speed of the liquid in the inlet port with the advantageous result that in this manner undesired effects of turbulence are eicientlv avoided and that-this improved pump may .be .particularly used for the delivery of all ,such liquids which arc not to be stirred, for instance, milk, beer, wine, foil, etc. On the .other hand, in the case of other liquids which may Abe readily stirred, by increasing the speed of the rotor the output of the pump will be considerably vhigher than that of the known pumps.

. It has to be understood that the present invention is by no means restricted to the -embodiment as described and shown, but that amendments and modifications may be made therein in as far as minor details of form and construction of parts are concerned, and ,that such amendments and modications are -to be considered as falling within 'the scope Aof the invention as clearly outlined and set forth in'the appended claims.

What vI claim as new and desire 'to secure by Letters Patentis:

l. In 'a low-speed rotary wing ypump of the .type having a cylindrical casing with tangential Vintake and discharge ports, a cylindrical rotor eccentrically mounted in said casing, a passage extending diametrically through said rotor and a pair of spring-loaded wings movably arranged in .said passage, and shaft means for rotating said rotor, the `improvements in said rotor consisting of two cast cup-shaped members adjacent one another, each of said members comprising a cylindrical wall provided with a pair'of diametrically opposed slots, an end wall vhaving a transverse internal groove registering with said diametrically opposed slots in said cylindrical wall, and beingadapted 'for guiding said wings therein, said diametrically opposed slots in one of said members registering with the corresponding slots in the other member; and a pair of parallel transverse walls extending from the edges of Aone slot to the corresponding edges of the opposite slot, thereby providing one half of said passage, the free edges of said cylindrical wallsof said two cup-.shaped members being provided with recessed rims for overlapping one another when assembled to form said rotor.

2. A low-speed rotary pump of the type comprising a-cylindrical casing with tangential intake and discharge ports, a cylindrical rotor eccentrically mounted in said casing, a passage extending diametrically through said rotor and a pair of spring-loadedwings movably arranged in said passage, and shaft means for rotating said rotor, wherein said rotor comprises .two cast cup-shaped members, each of which has its cylindrical wall provided .with a pair of diametrically opposed slots and a ,pair of parallel transverse wallsextending from the edges of one slot to vthe corresponding edges of the opposite slot and providing between themselves one half .of the said passage, the free edges of said cylindrical walls of said two cupshaped members having recessed rims for overlapping one another when assembled to folm the said rotor, and wherein sleeve portions are provided at'the outer surface of vthe Yend walls of 'both said cylindrical casing and said rotor, two individual shafts being rotatively mounted in said vsleeve'portio'ns of said Ycasing and'terminating with- References Cited in the le of this patent UNITED STATES PATENTS MacNish Apr. 14, 1908 Chase Apr. 26, 1927 6 Barnes July 3, 1928 Spotz' Sept. 5, 1950 Curtis et a1. Feb. 6, 1951 FOREIGN PATENTS Switzerland July 16, 1931 France Jan. 10, 1953 

